Approximately 35% of men diagnosed with prostate cancer will experience biochemical, i.e., prostate-specific antigen (PSA), recurrence within 10 years following localized treatment, indicating that the cancer may have returned. Androgen deprivation therapy (ADT) is a mainstay treatment for these individuals. Despite the clinical benefits, there is evidence that ADT may be associated with objectively-assessed cognitive impairment (assessed by neuropsychological tests), but there are also studies that note minimal or no impairments in ADT patients compared with healthy control groups. Our preliminary work indicates that ADT patients report problems with cognitive dysfunction, and further underscores research demonstrating that subjective cognitive impairments are associated with reduced quality of life and distress among cancer patients (including prostate cancer). Although objective assessments of cognitive functioning play an important role in the assessment of cognitive functioning, they may not always capture the subjective impairments that patients are actually experiencing in their day-to-day lives. These differences in assessment domains could be the reason for the commonly reported low correlations between objective and subjective cognitive functioning. In addition to subjective cognitive impairments, our preliminary work also suggests that ADT patients may experience neurobehavioral dysfunction (i.e., the behavioral signs and symptoms associated with neurological dysfunction such as apathy and neurofatigue). Hence, the goal of this study is to explore and document patients' real-world experience (i.e., subjective experience) of impairments in cognitive and neurobehavioral functioning following the start of ADT. We also aim to explore and document the impact of any cognitive and neurobehavioral impairments upon daily functioning and quality of life (including in the areas of work, relationships, and activities of daily living), as well as the strategies patients have used o cope with or compensate for any cognitive and neurobehavioral impairments. We plan to conduct in-depth semi-structured interviews with 20 nonmetastatic ADT patients and with a comparison group of 20 nonmetastatic PC patients who have not undergone ADT using the Common-Sense Model of Illness Representation to guide the content of our inquiry. We also plan to use neuropsychological assessments to explore any group differences (i.e., between patients with objectively-assessed cognitive impairment and those without such impairment) in the nature and severity of subjective cognitive impairments. This study is innovative as it is the first to comprehensively explore in ADT patients i) subjective cognitive functioning through in-depth interviews, ii) neurobehavioral impairments in ADT patients, iii) the impact of such impairments upon functioning and quality of life, and iv) the compensatory and coping strategies that patients may be using. The study is also innovative in using a multidisciplinary approach to investigating these issues. Given the increasing use of ADT with prostate cancer patients, this qualitative information will be critical for the design of appropriate and targeted rehabilitation interventions to help patients with subjective cognitive and neurobehavioral problems associated with ADT use. PUBLIC HEALTH RELEVANCE: The proposed study will increase our knowledge regarding the kinds of changes to cognitive functioning (e.g., memory and attention) and neurobehavioral functioning (e.g., lack of initiation and brain tiredness) that prostate cancer patients experience when treated with androgen deprivation therapy (ADT). It will also improve our knowledge regarding how patients are affected by these changes in their daily lives and any coping strategies they use to deal with them. Given the increasing use of ADT, this qualitative information will be critical for the design of appropriate and targeted interventions to help prostate cancer patients who experience these problems.